It might come as a shock, but US eggs are actually illegal in British and EU supermarkets and EU eggs are forbidden by law in US supermarkets.
The United States Department of Agriculture forbids US supermarkets to sell British eggs or eggs produced from any other country in the European Union, because they go on the market without being washed. US farmers have to undergo a strict series of procedures in order to clean their eggs from any bacteria that might contaminate the product. According to the USDA, an unwashed egg isn’t suitable for sale. On the other hand, the EU countries usually sell unwashed eggs for a variety of reasons. For one, it’s believed that the unwashed eggs mean that the eggs are coming from an actual hen and they also encourage proper husbandry. The second main reason for the unwashed eggs is that a careless washing procedure might actually contaminate the egg and do some serious damage to the product.
As strange as it may sound, this problem is more complex than it seems.